This invention relates to a seal belt assembly utilized for closing off the top of a compartment or cabinet in which operations are performed on workpieces within the compartment or cabinet. There are many operations, such as blasting and spraying, which are performed in relatively large compartments or cabinets in which the operative device for conducting such spraying or blasting is controlled by a robot that moves across the top of the compartment. In one of these types of apparatus, as disclosed in U.S. Pat. No. 4,882,881 entitled ROBOT POSITIONER AND SEAL ARRANGEMENT FOR A CLOSED CHAMBER, a seal belt is used attached to a carriage which supports a mast which extends downwardly into the compartment or cabinet. The operative device that does the blasting or spraying is mounted at the lower end of the mast. In the operation of such devices, the atmosphere within the compartment becomes filled with undesirable material that has to be prevented from escaping from the compartment. The apparatus of U.S. Pat. No. 4,882,881 includes a belt secured to the longitudinal sides of the carriage and continuously covering the top of the compartment. Although this belt has a decided advantage for containing the polluted air within the compartment, it has a safety hazard and also the noise transmitted through the ceiling by the operative device within the compartment is very undesirable.
In apparatus of the above type, it is essential that a catwalk be provided along one of the sides and above the top of the compartment or cabinet for maintaining the robot equipment located above the cabinet. Thus, a hazard exists that a worker in making repairs on the equipment could accidentally step on the belt, which appears to be rigid and sufficiently strong to sustain a person's weight, but which is not. Thus, the safety hazard referred to above exists in such prior art apparatus. Further, prior belts do not contain the noise generated by the operating device within the cabinet. The present invention solves this problem as will be described hereinafter.